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Spontaneous calcium permeability of ionic channel of P2X receptor after substitution ofconserved tyrosine in the 1st transmembrae domajn
Rupert, Marian ; Zemková, Hana (advisor) ; Balík, Aleš (referee)
Purinergic receptors are membrane ion channels that are activated by extracellular ATP. In vertebrates, seven genes encode subunits of P2X receptors. The subunits, designated P2X1-7, are 40 - 50% identical in amino acid sequences. P2X receptors are composed of three subunits and are found as homo- and heterotrimers in tissues of vertebrates. P2X receptors have a wide distribution in the organism, functional receptors are found in neurons, glial cells, muscle cells and also in nonexcitable tissues as epithelial, endothelial, and in hemopoietic tissue. Purinergic signalling plays an important role in pain transmission, at CNS injury and immune processes. P2X receptor subunit consists of two transmembrane domains, extracellular domain and intracellular N-and C-termini. Each transmembrane domain contains two amino acids conserved across all P2X subunits. In the first transmembrane domain receptor P2X2 are that Gly30 and Tyr43. In previous experiments performed on P2X2 receptor, electrophysiological measurements demonstrated that substitution of conserved Tyr43 in the first transmembrane domain with alanine prolongs the deactivation time of ion channel after agonist wash out. This work is focused on clarifying the role of conserved tyrosine in the process of opening and closing of ion channel of P2X...
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Calcium signalling in astrocytes under physiological and pathological conditions
Svatoňová, Petra ; Anděrová, Miroslava (advisor) ; Kolář, David (referee)
Calcium signalling in astrocytes represents an important component, which enables proper neuronal functioning under physiological conditions. Alterations in Ca2+ signalling, accompanied by an increase in intracellular calcium levels is a hallmark for numerous pathological states of central nervous system, such as traumatic and ischemic brain/spinal cord injuries, epilepsy as well as neurodegenerative diseases, such as Alzheimer's disease and psychiatric disorders, such as schizophrenia. The research analyzing the molecular components of astrocytic Ca2+ signalling can help us understand the control mechanisms used in calcium signalling and thus be greatly beneficial for further therapeutic research. Powered by TCPDF (www.tcpdf.org)
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The role of astrocytes in the formation of brain edema
Heřmanová, Zuzana ; Anděrová, Miroslava (advisor) ; Pačesová, Dominika (referee)
Brain edema is a cause of mortality accompanying number of pathologies such as ischemia, traumatic brain injury, tumors or liver and kidney failure. It is described as a process of osmotic and water flux alterations, which lead to cell volume changes and to an increase in intracranial pressure. Brain edema is usually classified into two types: vasogenic and cytotoxic. Development of vasogenic edema is connected to the blood brain barrier disruption. Water accumulates in the extracellular space and exerts pressure on the cellular compartments of the tissue. The cytotoxic type of edema is characterized by water accumulation within the cells. The process of cellular volume enlargement is termed cellular swelling. Cytotoxic swelling is usually connected to glial cells, namely astrocytes, as these cells represent a part of the blood brain barrier and thus they influence homeostasis inside the brain. Water flows across cytoplasmic membrane through a system of specialized channels - aquaporins. For the brain edema formation, aquaporin 4 is the most important. It is localized on astrocytic membranes and using aquaporin-null mice, it has been shown, that it participates in water clearance in physiological and pathological conditions. Since the water fluxes are passive, the driving force for edema formation...
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Optimization of a method for the determination of inorganic ions using capillary electrophoresis
Špačková, Simona ; Bezděková, Jaroslava (referee) ; Vaculovičová, Markéta (advisor)
Inorganic ions are one of the most important group chemicals. Their importance is crucial for all living organisms on the planet and monitoring of their content is essential for this purpose in clinical or environmental analysis but also in the food industry, agriculture or many other industries. Many analytical methods for ion detection have been designed and used, depending on the area of their use. Recently, numerous methods have been adapted to areas where not primarily intended. One such methods may be, for example, laser ablation with inductively coupled plasma mass spectrometry, which has recently begun to affect the analysis of biological samples. As a complementary method, able to detect also non-metallic ions is capillary electrophoresis. In this master thesis, the possibility of applying capillary electrophoresis with indirect photometric detection for the separation of inorganic ions in cell lysates of HeLa cells by capillary electrophoresis was verified. Main attention was paid to chloride ions. The ability to separate inorganic compounds in cellular material using salicylic acid as an absorbing anion in the base electrolyte was tested.
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The role of AQP4 and TRPV4 channels in the ischemic brain edema: focusing on glial cells
Kročianová, Daniela ; Anděrová, Miroslava (advisor) ; Máčiková, Lucie (referee)
Cerebral ischemia, also known as stroke, is one of the most common causes of death. It is accompanied by the formation of edema, which can be characterized as an influx of water and osmolytes into the brain, causing volume alterations. We recognize two types of cerebral edema - vasogenic, characterized by the disruption of the blood-brain barrier (BBB) and increase of the extracellular volume, and cytotoxic, caused by the increase of the volume of cells, mainly glia. The major contributors to the formation of cytotoxic edema are the astrocytes, which, in physiological conditions, are responsible for the maintenance of the BBB and keeping the homeostasis of the brain and spinal cord or central nervous system. The mechanism responsible for the process of volume and osmotic changes are the transmembrane channels, mainly aquaporin 4 (AQP4) and transient receptor potential vanilloid 4 (TRPV4). AQP4 is the main pathway for water influx as well as efflux when the edema subsides. TRPV4 is likely responsible for the maintenance of the osmotic balance of the organism, although its precise role in the formation of the edema has not yet been fully elucidated. The main aim of this thesis was to categorize the types of cerebral ischemia and edema, and to describe the process of cerebral edema formation and the...
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The role of AQP4 and TRVP4 channels in the ischemic brain edema: focusing on glial cells.
Kročianová, Daniela ; Anděrová, Miroslava (advisor) ; Máčiková, Lucie (referee)
Cerebral ischemia, also known as stroke, is one of the most common causes of death. It is accompanied by the formation of edema, which can be characterized as an influx of water and osmolytes into the brain, causing volume alterations. We recognize two types of cerebral edema - vasogenic, characterized by the disruption of the blood-brain barrier (BBB) and increase of the extracellular volume, and cytotoxic, caused by the increase of the volume of cells, mainly glia. The major contributors to the formation of cytotoxic edema are the astrocytes, which, in physiological conditions, are responsible for the maintenance of the BBB and keeping the homeostasis of the brain and spinal cord or central nervous system. The mechanism responsible for the process of volume and osmotic changes are the transmembrane channels, mainly aquaporin 4 (AQP4) and transient receptor potential vanilloid 4 (TRPV4). AQP4 is the main pathway for water influx as well as efflux when the edema subsides. TRPV4 is likely responsible for the maintenance of the osmotic balance of the organism, although its precise role in the formation of the edema has not yet been fully elucidated. The main aim of this thesis was to categorize the types of cerebral ischemia and edema, and to describe the process of cerebral edema formation and the...
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Electrophysiological characterization of Kir2.1 membrane channel
Měsíčková, Klára ; Chmelíková, Larisa (referee) ; Svoboda, Ondřej (advisor)
The topic of this thesis is electrophysiological characterization of Kir2.1 membrane channel. Inward rectifier potassium channel Kir2.1 is located in muscular, heart and nerve cells and its dysfunction causes various diseases. Practical part of this stage is focused on cultivation of the HEK293T cell line that is used to transfection of the plasmid Kir2.1 and subsequent measurement of the ionic current through the electrophysiological method patch-clamp in whole-cell mode.
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The role of astrocytes in the formation of brain edema
Heřmanová, Zuzana ; Anděrová, Miroslava (advisor) ; Pačesová, Dominika (referee)
Brain edema is a cause of mortality accompanying number of pathologies such as ischemia, traumatic brain injury, tumors or liver and kidney failure. It is described as a process of osmotic and water flux alterations, which lead to cell volume changes and to an increase in intracranial pressure. Brain edema is usually classified into two types: vasogenic and cytotoxic. Development of vasogenic edema is connected to the blood brain barrier disruption. Water accumulates in the extracellular space and exerts pressure on the cellular compartments of the tissue. The cytotoxic type of edema is characterized by water accumulation within the cells. The process of cellular volume enlargement is termed cellular swelling. Cytotoxic swelling is usually connected to glial cells, namely astrocytes, as these cells represent a part of the blood brain barrier and thus they influence homeostasis inside the brain. Water flows across cytoplasmic membrane through a system of specialized channels - aquaporins. For the brain edema formation, aquaporin 4 is the most important. It is localized on astrocytic membranes and using aquaporin-null mice, it has been shown, that it participates in water clearance in physiological and pathological conditions. Since the water fluxes are passive, the driving force for edema formation...
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